We have two sources of informations about Skills training versus experience

First one i met was is the wiki showing a graph

So according to the wiki graph for Primary skill we should need 3750 xp to go from 75% to 76% wich, after some tests is obviously not true.

The second source is a reply from Overlord

Quote

Each additional qualification is twice more expensive.

Translating the numbers given by Overlord into a formula was more succesfull

xp you need to go to the next % is : xp=50*(100^(1/100))^k

k being the % you are

For secondary skills replace the 50 in the above formulae with 100, 200 or 400

This gives exactly 500xp to go from 50% to 51% and 5000xp to go from 100% to 101% (wich make no sense that's why i first went to an other formulae)

Here is the new graph i have obtained with this formula :

So it's a total of 77543 xp for your Primary skill to go from 75% to 100%, 220064 xp for 1st Secondary skill to go from 0% to 100%, 440128 xp for 2nd Secondary skill to go from 0% to 100% and 880255 xp for 3rd Secondary skill to go from 0% to 100%

Other points i have found while doing this tests :

- I have seen somewhere in this forum that the xp you gain from a battle is divided between your crew memebrs but all my test show that each crew member get all the xp (and that's nice because my T-28 as 6 of them !)

- A dead crew member get a 10% reduction (rounded to the highest) to the xp he would have normaly got from the battle (maybe this is a well known info but i didn't find it before)

- The double xp for first win is taken into account for the % calculation but not on xp shown in the crew member's stats (so the xp you see in crew member's stats is lower than what he really have)

Hope this will help ...